AM_Na3K7MgF3 Formula: (Na.3 K.7) Mg F3 Name: Na.3K.7MgF3 Unit cell: 3.9659 3.9659 3.9659 90.0 90.0 90.0 , V=62.38 Space group: PM3M (221)

Chakhmouradian A R , Ross K , Mitchell R H , Swainson I , Physics and Chemistry of Minerals , 28 (2001) p.277-284, The crystal chemistry of synthetic potassium-bearing neighborite, (Na1-xKx)MgF3, Sample x = .70